ITC on Motor Vehicles is specifically BLOCKED under Section 17(5) of the CGST Act 2017. So you cannot claim ITC on GST paid on purchase of Motor Bikes for Office Staff.
As per the Provision of Section 17(5) clause (a) of the CGST Act 2017, ITC on Motor Vehicles having approved seating capacity of less than or equal to 13 ( including the Driver ) is not eligible.